Fraudulent telephone calls are a major source of revenue loss to telephone service providers. They also result in customer dissatisfaction when tolls are inadvertently charged to the subscriber as a result of fraudulently placed calls. Present systems use batch mode analysis of call details and sometimes manage to detect some types of fraud. This arrangement requires the telephone company to communicate with the culprit to end the abuse. It entails a delay in the prevention of fraud.
The aforementioned U.S. Application, Ser. No. 07/891,347 filed May 29, 1992, now U.S. Pat. No. 5,375,244 discloses an access control system which uses "soft" decisions to determine if a user's profile are most like a valid user or a hacker. It clusters data for both and compares the user with both to obtain statistical probabilities of fraudulent access.
An object of the invention is to overcome the disadvantages of prior systems.
Another object of the invention is to detect and block or disconnect fraudulent access demands in real time.